All the ingredients are there for a large rainfall event to sweep the nation but it does come in parts, across the next 7-14 days.

Clearly the remains of Tiffany are the most present cause of that rainfall opportunity, it has been a very wet night over the north of the nation as she has worked her way through to the western Top End with gusty winds and heavy rainfall and thunder. The weather is expected to progress into the Kimberly today.

Down over the southeast and east, we have the last of the upper troughs for now, expected to sharpen up bringing further showers and thunderstorms today to eastern SA but more likely over western NSW and VIC where the coverage of storms will be widespread. Severe thunderstorms scattered and all modes of severe weather are possible. This will repeat again on Friday for the eastern states, though a drier westerly change may bring about an end to the humid and unsettled weather for a period over the southeast this weekend.

The remainder of SA and WA stays dry for a while, but I would be keeping watch on the tropical moisture lurking to the north. This is likely to spill south, mainly impacting northern SA at this time, but we have seen in previous runs, that the moisture may indeed fall south throughout the entire state, which would bring a month's worth of rainfall to the Ag Areas in SA. It is a chance.

Further on, the moisture of the east remains in place so still humid, unsettled with periods of showers and thunderstorms. Then another trough may develop over SA and NSW bringing the next chance of heavy rainfall and thunderstorms to the southeast from later next week which would put some pressure on river systems throughout the region with heavy falls possible.

Over the tropics, pseudo monsoonal conditions are expected to continue in the wake of TIffany. She has allowed a more convergent and unstable northwest flow to be brought in and high levels of moisture means heavy showers and gusty storms will continue for much of the tropics for a while. Out of heavy convection offshore we may see another tropical low form later next week which could offer some hope of rainfall returning to WA. This would spark the third rainfall event for the nation.

So lots on - lets have a look


Rainfall Next 10 Days

Rainfall is getting interesting now and I will have more on that in the models and rainfall post coming up after this. I just want to point out that the rainfall forecast is still low confidence in light of the uncertainty surrounding the movement of the weakening tropical feature over the NT and WA and where does that go? Does it move southeast, south or west? That will have massive implications on the rainfall spread and expectations next week. Before then, hit and miss lotto showers and thunderstorms for eastern SA, VIC, NSW and QLD through the coming 2-3 days before the unsettled weather with a trough moves away. The weather is dynamic, high energy and it will continue to evolve over the coming days.

The Remains of Tiffany

Tiffany moved through Katherine at about midnight local time bringing squally rain, the system is now over the Gregory district of the NT and is slowing down. The remnant circulation will still produce heavy monsoonal rainfall for the NT and northern WA today with thunderstorms locally severe. The system remains slow moving through Saturday over the Kimberly before the system shoots off to the south and brings heavy rainfall for the interior.

Flood Watch NT and WA

Flooding is possible from today through the weekend over the Top End and Kimberly. The risk will likely spread through the interior over the weekend into next week and charts for outback areas into SA will be issued ahead of time. The Central Top End has dodged a bullet which is great news even with the minor flooding in pockets overnight.

Thunderstorm Forecast NSW

Severe thunderstorms are possible over a wide area today. Remain weather aware. The main window for storm activity will be between 2pm-10pm with severe weather likely in this time frame. The storms will progress eastwards during the afternoon and evening before weakening. Thunderstorms are forecast to develop across eastern SA and western NSW and northwest VIC during Thursday afternoon and evening. Storms are expected to organise into multicells with flash flooding a high to very high risk through the pink zone. There will also be a risk of damaging winds and large hail as well in this zone. The thunderstorms are expected to be more scattered in nature through central VIC and NSW, and the risk tapers off further north through NSW and eastern VIC. Thunderstorms may develop into a squall line over northern VIC and southern NSW where damaging winds progress eastwards. Storms may also turn supercellular over parts of eastern SA and western NSW during the afternoon and evening where giant hail and destructive straight line winds/isolated tornadoes are possible.

Flash Flood Risk Thursday

A high to very high risk of flash flooding with severe thunderstorms along and to the east of a surface trough over the west of NSW and eastern SA. Some storms could drop more than 50mm in an hour.

Damaging Winds Risk Thursday

Damaging winds are a very high risk through eastern parts of SA near a trough, as storms form and strengthen over the region. The storms will progress eastwards into NSW and northwest VIC mid to late afternoon and there is a moderate chance of damaging winds with a squall line moving further east through NSW and VIC at night.

Large Hail Risk Thursday

Thunderstorms that form immediately on the trough will carry a moderate to high chance of producing large hail through the afternoon and evening. The focus of the hail risk slowly moves eastwards towards western NSW and northwest VIC during the late afternoon and evening.

Tornado Risk Thursday

Thunderstorms that turn supercellular, carry the risk of giant hail and isolated tornados in the areas identified.

Euro 12Z - CAPE Values - Next 3 Days

The potential energy that is available is up to 2000j/kg which is sufficient for severe thunderstorms and deep convection leading to the severe thunderstorm possibility. The winds aloft also supportive of rotating updrafts which could see large/giant hail and damaging to destructive winds with intense rainfall possible. This risk will slowly move east through the period.

Thunderstorm Forecast Thursday

Thunderstorms likely to continue right across the north with dangerous thunderstorms with destructive winds over the NT quite possible. Thunderstorms expected to turn more widespread over the southeast with a trough deepening through SA. This trough is expected to bring a risk of severe storms, with all modes of severe weather possible.

Thunderstorm Forecast Friday

Thunderstorms contract slowly eastwards on Friday with the low deepening along a trough over the southeast. This will create a dynamic environment for thunderstorms to turn severe, all modes of severe weather is possible with the chance of some giant hail and destructive winds in a few storms. Thunderstorms will stretch into QLD but these will be less severe than further south. Strong storms continue for northern Australia, some severe with heavy rainfall leading to flash flooding.

Thunderstorm Forecast Saturday

The remains of Tiffany is expected to move southwards and merge with a trough over inland areas of the nation leading to more widespread showers and thunderstorms developing during the day with locally heavy falls leading to flash and riverine flooding. The same can be said for the east with storms continuing from Friday into Saturday and this will contract was through the day, with further thunderstorms likely to form, leading to all modes of severe weather possible for QLD, NSW and the ACT. Clearing conditions through VIC. Afternoon storms possible near a developing heat trough over in the west and gusty showers and thunderstorms possible over the Top End.

DATA - More details in the video.

12Z Euro - Surface Pressure Pattern and Rainfall Distribution - Next 10 Days

The pattern is evolving and the models have been playing catch up it seems, with really poor guidance from the major modelling on Tiffany as she moved through northern Australia. But now we are seeing a better agreement on the moisture being transported through Central Australia and through SA into the eastern states next week. That will lead to widespread rain and thunderstorms, with locally heavy falls about leading to flooding across multiple states. The weather is expected remain very humid now over the east and southeast for the majority of the period, bar a break in the unsettled warm weather over coastal areas of SA and VIC. So if you are living in the southeast and east through Central Australia, pay attention to forecasts.

12Z Euro - Precipitable Water Values - Next 10 Days

And all of a sudden the models are aligning in suggesting the moisture over the north and east of the nation will now come further south into SA, with a widespread rainfall event likely to be born out of the remains of Tiffany. Inland flooding is possible from the NT through Central Australia, through SA and into western QLD, NSW and perhaps northern VIC. Significant rainfall is likely through next week and will keep an eye on trends. The west looking fairly dry for now but there is a chance of another cyclone/low forming off the Kimberly with that weather possibly moving south through the state in the medium term. The tropics remain very soupy and unsettled as you can see ahead of the developing monsoon later in the month.

12Z Euro - Rainfall Accumulation - Next 10 Days

More information in the video and in the rainfall and model update.

12Z GFS - Rainfall Accumulation - Next 10 Days

More information in the video and in the rainfall and model update.

12Z CMC - Rainfall Accumulation - Next 10 Days

More information in the video and in the rainfall and model update.

12Z Euro - Rainfall Accumulation - Next 15 Days

More information in the video and in the rainfall and model update.

12Z GFS - Rainfall Accumulation - Next 16 Days

More information in the video and in the rainfall and model update.